1. Technical Field
The present invention relates to an assembly for protecting a vehicle occupant during a collision. Particularly, the present invention relates to a vehicle seat which moves during a collision to minimize occupant rebound and an occupant seat belt restraint system which is tightened about the occupant in response to the movement of the seat.
2. Description of the Prior Art
Seats which move forward during a collision to minimize occupant rebound are known, and occupant seat belt restraint systems for use in vehicles are also known. A known occupant restraint system typically includes a lap belt and a shoulder belt. Belt pretensioners that pull the shoulder belt tightly against the occupant during a collision are also known. One belt pretensioner is disclosed in U.S. Pat. No. 4,449,443. The belt pretensioner disclosed in U.S. Pat. No. 4,449,443 requires a separate energy source in the form of pressurized fluid to actuate belt tightening.
Certain belt pretensioners utilize the momentum resulting from movement of the seat to actuate belt tightening. Such a belt pretensioner is disclosed in U.S. Pat. No. 4,159,120. Upon forward seat movement during a collision, a mechanism is actuated which tightens the shoulder belt about the occupant. The belt pretensioner disclosed in U.S. Pat. No. 4,159,120, must be installed in the vehicle separate from the seat.
Belt restraint systems mounted to a seat minimize vehicle interior space occupied by the seat and belt system assembly and permit the seat and belt system to be installed in the vehicle as a unit. Such assemblies are disclosed in U.S. Pat. Nos. 3,552,795 and 3,832,002. These patents disclose a seat which is movable relative to the vehicle upon a collision. The seat includes occupant restraint seat belts connected to, and movable with, the seat. However, the belts do not tighten about the occupant during a vehicle collision.
The automotive industry has, for a long time, been working on a variety of safety concepts for protecting a vehicle occupant. The safety concepts include (i) an occupant seat which moves forward during a generally head-on collision thereby minimizing the distance of occupant rebound during the collision, and (ii) tightening a seat belt about the occupant during a collision to minimize occupant movement relative to the seat. To applicant's knowledge, however, no one has combined these safety concepts into one structure which can be installed as a unit in the vehicle thereby simplifying installation on an assembly line and limiting space requirements.